Your suggested code above is a good start. However, I still have some lingering problems:

~ I would like to have substantial markers for each data point (e.g. o or triangle markers), particularly for Data Set B, which, if the markers aren't enlarged, appear only as tiny, almost invisible single pixels. However, I can't seem to change the marker size using plotyy() in the same way that this can easily be done using plot().

~ I'm not sure how to specify the axes limits. I would like the left Y axis to have limits of [-2, 2] and the right Y axis to have limits of [0,20] (or, if possible, to have the 0 values of both axes line up, and include -20 as the lower limit on the right axis). It doesn't appear that the 'Alim' property is what I should modify, and if I try to do this, nothing changes. If there is only one variable for the axis, how would it be possible to change the properties of 2 different axes?

~ Also, I would like to add labels to both Y axes, but similarly to the axes limits issue above, I'm not sure how to specify this using plotyy(). If I try to do

set(AX, 'Ylabel', 'Mean Rating Value'); ... I get an error that the 'value must be a handle'; however, if I try set(H1,'Ylabel','Mean Rating Value'); , I get:??? Error using ==> setThere is no 'Ylabel' property in the 'lineseries' class.